1. Technical Field
The present disclosure relates to a power supply circuit for supplying power to a central processing unit (CPU).
2. Description of Related Art
Referring to FIG. 3, a typical power supply circuit for supplying power to a CPU includes a pulse-width modulation (PWM) controller and a driving integrated circuit (IC). The driving IC is connected to a pair of MOSFETS. The PWM controller outputs a PWM signal to the driving IC. The driving IC outputs signals to switch on/off the MOSFETS according to a sequence determined by the PWM controller, thereby regulating a voltage output to the CPU. The driving IC may be an ADP3120A chip which has a Vcc power pin. The ADP3120A chip can work with a voltage in a range of 4.15V-13.2V. Preferably, the ADP3120A chip should work at an optimized voltage (e.g., 10V). If the ADP3120A chip is supplied with the optimized voltage, a conversion efficiency of the ADP3120A chip is optimized, which reduces power consumption in the power supply circuit. However, the driving IC of the typical power supply circuit is supplied with a 12V voltage rather than the optimized voltage. A conversion efficiency of the driving IC is not optimized, and waste energy.